The present invention relates to a method for producing an adhesive closing element with a plurality of hook elements that form a single piece with a support. The hook elements are in the form of rods having enlargements on the ends. A thermoplastic synthetic resin in a plastic or fluid state is fed into the gap between movable tools The tools are driven in such a manner that the support is formed in the gap and is conveyed in a direction of conveyance, whereby book elements are formed on both sides of the support by forming elements agog on both sides on the gap.
A method of forming adhesive closing elements in disclosed in publication WO 95/01863. The execution of this method takes place in a disadvantageously costly manner, when finely structured hook elements are to be produced in great number and are arranged on the support in correspondingly high packing density. As a result, the production of the forming elements, which form the hook elements, is extraordinarily costly.
Objects of the present invention are to provide a method facilitating low-cost production of adhesive closing elements with finely structured hook elements arranged in high packing density.
These objects are attained according to the present invention by arranging hollow spaces passing through a first screen and a second screen on the interior of the first screen for forming elements. The hook elements are formed in the hollow spaces in such a manner that the thermoplastic synthetic resin hardens at least partially in the hollow spaces of the screen.
The formation of the hook elements using two screens engaging on one another advantageously permits producing very finely structured hook elements, as they are provided in the micro-adhesive closing elements (see DE 196 46 318 A1), at low cost. The second interior screen engaging on the exterior screen involves an additional forming element during the forming of the rod forming the hook elements, and also involving its end configuration.
In this manner, the advantage is obtained that no particular requirements need be met concerning the geometry of the openings of the screen, because the shape and condition of the enlarged end area of the rod formed by the filled-in synthetic resin are obtained exclusively through the hollow spaces of the interior screen. The diameter of the interior screen hollow spaces is selected to be somewhat greater than the diameter of the hollow spaces of the exterior screen. The differential in diameter is selected so that the withdrawal of the rod can take place with the end enlargement formed by a hollow space of the interior screen and can occur following hardening or partial hardening of the synthetic resin without any difficulties. Costly processing for the formation rounded edges is not required around the hollow spaces of the interior screen or around the hollow spaces of the exterior screen.
The method according to the present invention can be carried out in such a manner that the hook connection effect of the adhesive closing element is almost identical on the two sides. For this purpose, the hook elements of both sides can be configured to be identical, in terms of both their packing density and also their geometry and dimensions. Such an adhesive closing element is suitable particularly for the formation of secure, permanent hooking on two sides.
Adhesive closing elements can have different adhesive properties on the two sides as a result of different packing densities, form design and/or dimensions of the hook elements on the two sides. These closing elements can preferably be used for detachment of the hooking connection limited to only one side. This arrangement, for example, is advantageous in the case of carpet-laying systems.